Former glamour model Katie spoke about Kieran during an appearance on The Wright Stuff yesterday (21 June), adding that her relationship with Alex was a "rebound" fling.
"I don't know why I married him so quick, I was in cuckoo land," she said. She also spoke about her book and confirmed that Kieran is "The One".
It now appears Alex has hit back at Katie, who he married following her divorce from Peter Andre, mocking the title of her novel.
Taking to Twitter, he said: "Surely a typo, 'He's The One - for now' the title should read?"
Alex then made a dig which suggested he is fed up with Katie talking about their failed marriage in the public eye - and in her forthcoming autobiography, Lipsticks, Love and Lawsuits.
Surely a typo "He's the One -for now" The title should read? I have my ex eife to thank for not having any skeletons remaining in my closet— Alex Reid (@AlexReid) June 21, 2013
Earlier this week, Katie told Daybreak viewers that her autobiography is "disturbing and emotional", adding that it follows on from her marriage to Alex.
In the same tweet, cage fighter Alex continued: "I have my ex wife to thank for not having any skeletons remaining in my closet."
And he didn't stop there. Alex then joked that Katie's ex-boyfriend Leandro Penna, and presumably referring to her fling with Danny Cipriani, should "compare notes".
"Danni, Leo, fancy a beer tonight - compare notes?" he tweeted.
Katie has not yet responded.